净水厂污泥的磷吸附特性研究

为了实现净水厂污泥的资源化利用,对净水厂污泥的磷吸附特性进行了研究。通过吸附试验考察了对照土样和净水厂污泥的磷吸附能力,研究了温度、溶液初始pH值和初始浓度对净水厂污泥磷吸附的影响。结果表明,对照土样和净水厂污泥对磷的吸附都符合Langmuir吸附等温方程,净水厂污泥的磷吸附容量是对照土样的17倍;净水厂污泥对水中磷的吸附速率随温度的升高增大,随pH的增高降低,随初始浓度的升高增大;净水厂污泥对磷的吸附过程可以采用一级动力学方程描述;净水厂污泥具有作为污水除磷材料的巨大潜力。     

电絮凝法同步去除氨氮和磷的模拟试验

采用电絮凝法去除废水中的氨氮和磷,电极板采用铝板或不锈钢板,研究了电絮凝除磷热力学与动力学过程,考察了不同工艺参数对氨氮和磷去除效果的影响. 结果表明:相对于铝电极而言,不锈钢电极更适宜于电絮凝去除氨氮和磷;Redlich-Peterson方程能较好地描述电絮凝产生的絮凝体对磷的吸附行为,得到的Gibbs自由能变都在-20～0kJ/mol范围内,并且吸附是自发进行的吸热过程,升高温度有利于吸附;由于假二级动力学方程拟合时其相关系数(R2)均大于0.98,故假二级动力学方程更适宜描述电絮凝产生的絮凝体对磷的吸附动力学过程;随着电流密度的增加,氨氮和磷的去除率呈逐渐上升趋势;在强碱性条件下,氨氮的去除率相对降低,酸性条件下水中磷的去除率较高,随着溶液pH的增高,磷的去除率呈逐渐降低趋势. 去除氨氮和磷的能耗分别为0.15~0.50和0.02~0.04kW·h/g.      

沸石对水中磷吸附性能的初步研究

利用不同粒径的沸石对水中磷的吸附性能进行初步研究。结果表明：投加量7 g,反应时间60min,温度35℃,pH 3～9时沸石对水中磷的吸附效果最佳;沸石对磷的吸附动力学过程适合用拟二级速率方程进行拟合,拟合系数接近1;吸附等温线符合Freundlich方程所描述的规律,温度越高,沸石对磷的吸附性能越好;在相同的温度条件下,粒径越小的沸石对磷的吸附能力越强。     

固废基陶粒对含磷废水的处理研究

在前期研究固废基陶粒的制备及性能表征的基础上,该文采用静态和动态试验方法,开展固废基陶粒处理模拟含磷废水研究。结果表明：在初始浓度为17 mg/L和反应温度为293 K时,固废基陶粒对水中磷的平衡吸附量可达1.013 mg/g,Freundlich吸附等温模型和准一级动力学方程都能较好地描述该吸附过程(R²>0.95),且是一个自发的放热的物理吸附过程。在反应温度为293 K时,随着初始浓度由5 mg/L增至17 mg/L,基于固废基陶粒的固定床反应装置去除水中磷的穿透曲线变得越来越陡峭,穿透时间和饱和时间分别由34 h和60 h缩短至18 h和32 h,此外Yoon-Nelson固定床反应动力学方程能比较精确地描述动态除磷过程(R²>0.95)。     

锌锰电池正极材料净化模拟废水中磷的研究

研究利用废旧锌锰电池的阳极材料净化模拟废水中的磷,探讨了净化过程中pH、吸附剂用量、反应时间和磷初始浓度等操作条件对磷净化效果的影响,找出了适宜的操作条件并对净化过程的机理进行了分析。通过试验发现pH对磷净化过程有显著影响,含磷废水净化过程中适宜的pH为8.0;随着吸附剂加入量的增加和初始溶液的降低,磷的净化率逐渐增加。锌锰电池正极材料对水中磷的净化过程速度较快,5 min即可使磷的吸附率达到93.41%。对平衡吸附容量数据进行回归分析发现磷净化过程的吸附等温线可以用Langmuir方程和Freundlich方程表示,Langmuir方程参数Q0为12.41 mg/g,Freundlich方程参数n为2.927,用不同的动力学模型对试验数据进行回归分析发现吸附剂对水中磷的吸附过程符合假二级模型。锌锰电池正极材料可以有效净化废水中的磷。     

Ca/Mg负载改性沼渣生物炭对水中磷的吸附特性

为处理含磷废水和实现沼渣资源化利用,将农业废弃物沼渣制备成生物炭(ZZs),通过Ca Cl2和MgCl2溶液对其进行浸渍改性,探究改性沼渣生物炭(CMZZs)对水体中磷的吸附特征.结果表明,改性后沼渣生物炭钙镁含量分别是改性前的1. 3和15. 4倍; SEM-EDS、BET、FTIR和XRD等测定表明,改性未改变生物炭表面化学官能团种类,但改性后生物炭出现新的衍射峰,与标准卡片对比后认为可能存在Mg(OH)_2、MgO等物质.当温度为303 K,溶液pH为9. 0时,CMZZs最大吸附量为76. 92 mg·g~(-1),是改性前的30. 1倍.等温吸附实验数据符合Freundlich方程,为多层吸附.吸附动力学分析发现,改性后生物炭在100 min内基本达到吸附平衡,吸附过程符合假二级动力学方程,以化学吸附为主.上述结果说明钙镁改性沼渣生物炭对于去除水中磷具有潜在价值.     

改性芦苇生物炭对水中低浓度磷的吸附特征

为吸附处理低浓度含磷废水和实现芦苇资源化利用,将湿地植物芦苇制备成生物炭,通过负载氯化铁进行改性,探究了改性芦苇生物炭对水体中磷的吸附特征.结果表明,改性后芦苇生物炭的含铁量为11.98 mg·g~(-1),是改性前的44.7倍;改性芦苇生物炭p H_(pzc)为7.49,当溶液p H为7.0时,吸附效果最好;在磷溶液浓度为4.0 mg·L~(-1)、温度为298K时,改性芦苇生物炭平衡吸附量为0.658 mg·g~(-1),是未改性生物炭吸附量的34.6倍.研究不同温度下的吸附等温线,Langmiur方程很好地拟合不同温度的吸附等温线,该吸附是单层吸附,温度升高有利于吸附.吸附热力学研究表明,ΔG~θ0、ΔH~θ0和ΔS~θ0,说明该吸附是自发、熵增的吸热过程.假二级方程很好地拟合改性芦苇生物炭吸附磷的动力学数据,初始吸附速率随初始浓度的增大而增大,该吸附主要受颗粒内扩散控制.该研究为改性芦苇生物炭用于污水处理厂和水体深度除磷提供基础数据.     

鸡蛋壳对废水中亚铁离子的吸附研究

为研究鸡蛋壳对废水中亚铁离子的吸附效果,进行了单因素变量控制实验(如鸡蛋壳粉末的投加量、吸附温度、吸附时间)、等温吸附实验和正交实验。研究结果表明,鸡蛋壳用量在4 g的时候吸附效果最好;鸡蛋壳粉末对亚铁离子的吸附是吸热过程,随着温度升高,去除率也随之升高;去除率也随吸附时间增加而升高,在60 min左右达到吸附平衡。等温吸附过程中,能很好地符合Freundlich吸附等温式。通过正交实验,得出最佳实验条件:亚铁离子浓度40 mg/L,鸡蛋壳粉末3 g,吸附时间为50 min,吸附温度为50℃,在此实验条件下鸡蛋壳对废水中亚铁离子的去除率可达99.99%。     

蒙脱石对Co2+吸附机理和性能研究

随着锂电池的广泛使用,废弃锂电池中所含的钴元素以离子形式开始进入地下水中。文章以吸附水中钴离子为研究内容。系统研究了吸附时间、溶液浓度、温度以及pH值对其吸附性能的影响。结果表明:蒙脱石对钴离子的平衡吸附时间约为1 h;在303 K下蒙脱石对钴离子的最大吸附量约为30.77 mg/g,且吸附方程可以用Langmuir模型进行良好的拟合;吸附行为符合拟二级动力学方程;最佳pH环境为弱酸性。     

铁盐改性废弃蛋壳对水中磷的吸附特征研究

采用铁盐对废弃蛋壳进行化学改性,并研究改性蛋壳对水中磷的吸附特征.结果表明,改性蛋壳明显提高磷的吸附能力,磷在改性蛋壳中的吸附是一吸热过程,其吸附等温线符合Freundlich方程,磷在改性蛋壳中的吸附历时曲线遵循准二级反应动力学模型.溶液pH值显著影响磷在改性蛋壳中的吸附效果,当pH3时,改性蛋壳对磷具有吸附最大值.     

Sequestration of toxic Pb(Ⅱ) ions by chemically treated rubber(Hevea brasiliensis) leaf powder

Rubber leaf powder(an agricultural waste) was treated with potassium permanganate followed by sodium carbonate and its performance in the removal of Pb(Ⅱ) ions from aqueous solution was evaluated.The interactions between Pb(Ⅱ) ions and functional groups on the adsorbent surface were confirmed by Fourier transform infrared(FT-IR) spectroscopy,scanning electron microscopy(SEM) coupled with X-ray energy dispersive spectroscopy(EDX).The effects of several important parameters which can affect adsorption capacity such as pH,adsorbent dosage,initial lead concentration and contact time were studied.The optimum pH range for lead adsorption was 4-5.Even at very low adsorbent dosage of 0.02 g,almost 100% of Pb(Ⅱ) ions(23 mg/L) could be removed.The adsorption capacity was also dependent on lead concentration and contact time,and relatively a short period of time(60-90 min) was required to reach equilibrium.The equilibrium data were analyzed with Langmuir,Freundlich and Dubinin-Radushkevich isotherms.Based on Langmuir model,the maximum adsorption capacity of lead was 95.3 mg/g.Three kinetic models including pseudo first-order,pseudo second-order and Boyd were used to analyze the lead adsorption process,and the results showed that the pseudo second-order fitted well with correlation coefficients greater than 0.99.     

改性废报纸纤维对水中Cr(Ⅵ)的吸附研究

利用环氧氯丙烷与三甲胺对废报纸纤维进行改性制备阴离子吸附材料(CWNF),通过傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)、能谱(EDS)、热重分析(TGA)、比表面积(BET)对改性前后废报纸纤维进行表征,并研究其去除水中六价铬离子Cr(VI)的性能.结果表明,改性后废报纸纤维(CWNF)对Cr(VI)的吸附能力显著提高.当CWNF投加量为1g/L,溶液pH为1时,对100mg/L Cr(VI)的最大吸附量为38.66mg/g,平衡时间为60min,比改性前废报纸纤维(WNF)的吸附量(24.18mg/g)提高了59.88%.Langmuir与Freundlich等温吸附方程均能较好地描述CWNF对Cr(VI)的吸附特性,吸附动力学更符合拟二级速率方程.     

Adsorption of naphthalene onto a high-surface-area carbon from waste ion exchange resin

A high-surface-area carbon (KC-1) was prepared from waste polystyrene-based ion exchange resin by KOH activation and used for naphthalene adsorption. The carbon exhibited a good hydrophobic nature with developed porous structure, favoring the adsorption of organic compounds. The Brunauer-Emmett-Teller surface area and total pore volume of KC-1 were 3442.2 and 1.68 cm 3 /g, respectively, which can be compared with those of KOH-activated carbons prepared from other precursors. Batch experiments were carried out to investigate the adsorption of naphthalene onto KC-1. The equilibrium data were analyzed by the Langmuir, Freundlich, and Polanyi- Manes isotherms and agreed with the Polanyi-Manes Model. The adsorption of naphthalene depended greatly on the porosity of the carbon, and the dispersive interactions between naphthalene and carbon could be relatively weak. The pH variation in aqueous solution had little effect on the adsorption process. The equilibrium time for 0.04 g/L of carbon dose was around 5 hr. Different models were used to evaluate the kinetic data and the pseudo second-order model was suitable to describe the kinetic process of naphthalene adsorption onto KC-1. Regeneration of spent carbon could be carried out effectively by alcohol treatment. The results indicated that KC-1 was a promising adsorbent for the removal of polycyclic aromatic hydrocarbons from aqueous solutions.     

Sequestration of toxic Pb（II） ions by chemically treated rubber （Hevea brasiliensis ） leaf powder

Rubber leaf powder (an agricultural waste) was treated with potassium permanganate followed by sodium carbonate and its performance in the removal of Pb(II) ions from aqueous solution was evaluated. The interactions between Pb(II) ions and functional groups on the adsorbent surface were confirmed by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDX). The effects of several important parameters which can affect adsorption capacity such as pH, adsorbent dosage, initial lead concentration and contact time were studied. The optimum pH range for lead adsorption was 4–5. Even at very low adsorbent dosage of 0.02 g, almost 100% of Pb(II) ions (23 mg/L) could be removed. The adsorption capacity was also dependent on lead concentration and contact time, and relatively a short period of time (60–90 min) was required to reach equilibrium. The equilibrium data were analyzed with Langmuir, Freundlich and Dubinin-Radushkevich isotherms. Based on Langmuir model, the maximum adsorption capacity of lead was 95.3 mg/g. Three kinetic models including pseudo first-order, pseudo second-order and Boyd were used to analyze the lead adsorption process, and the results showed that the pseudo second-order fitted well with correlation coefficients greater than 0.99.     

Application of activated carbon derived from scrap tires for adsorption of Rhodamine B

Activated carbon derived from solid hazardous waste scrap tires was evaluated as a potential adsorbent for cationic dye removal. The adsorption process with respect to operating parameters was investigated to evaluate the adsorption characteristics of the activated pyrolytic tire char (APTC) for Rhodamine B (RhB). Systematic research including equilibrium, kinetics and thermodynamic studies was performed. The results showed that APTC was a potential adsorbent for RhB with a higher adsorption capacity than most adsorbents. Solution pH and temperature exert significant influence while ionic strength showed little e ect on the adsorption process. The adsorption equilibrium data obey Langmuir isotherm and the kinetic data were well described by the pseudo second-order kinetic model. The adsorption process followed intra-particle di usion model with more than one process a ecting the adsorption process. Thermodynamic study confirmed that the adsorption was a physisorption process with spontaneous, endothermic and random characteristics.     

木棉纤维对水中柴油的吸附性能

用木棉纤维作为吸附材料对含油废水进行吸附研究,考察了吸附平衡时间、等温吸附、以及溶液pH、溶液盐浓度等因素对油吸附的影响。溶液pH对吸附影响很小,在不同的盐浓度下吸附略有下降,木棉纤维吸附剂对0#柴油的吸附所需平衡时间为4h,在室温和pH=7左右的条件下,吸附材料对0#柴油的最大吸附量(qm)为(31±0.81)g/g,等温吸附线符合Langmuir和Freundlich模式,研究结果表明:木棉纤维对含油废水的吸附能在较短的时间达到吸附饱和,吸附量较大,对溶液环境的适应能力强,具有很好的应用前景。     

锆改性沸石对水中磷酸盐和铵的吸附特性

采用锆对天然沸石进行改性,并研究了锆改性沸石对水中磷酸盐和铵的吸附特性.结果表明,锆改性沸石对水中磷酸盐和铵均具有很好的吸附能力.锆改性沸石对水中磷酸盐和铵的吸附动力学过程满足准二级动力学模型.Langmuir、Freundlich和Dubinin–Radushkevich(D–R)等温吸附模型可以很好地描述锆改性沸石对水中磷酸盐的等温吸附行为.Langmuir等温吸附模型可以很好地描述锆改性沸石对水中铵的等温吸附行为.由Langmuir等温吸附模型计算得到锆改性沸石对磷酸盐和铵的最大吸附容量分别达到26.2,7.82 mg/g.热力学参数表明锆改性沸石对水中磷酸盐的吸附是自发的吸热反应过程.锆改性沸石对水中磷酸盐的吸附能力随着pH值的增加而降低.当pH4~8时,锆改性沸石对水中铵的吸附能力较高;当pH低于4或高于8时,对铵的吸附能力下降.水中共存的Cl-、SO42-、HCO3-和NO3-等阴离子对锆改性沸石吸附磷酸盐的影响很小,而共存的SiO32-对磷酸盐的吸附则具有较强的负面影响.水中共存的Ca2+和Mg2+对锆改性沸石吸附铵的影响较小,而共存的K+和Na+对铵的吸附则具有较强的负面影响.锆改性沸石吸附水中磷酸盐的主要机制是阴离子配位体的交换,吸附水中铵的主要机制是与沸石中可交换阳离子的离子交换.     

烟梗黄原酸酯吸附铜离子性能研究

以废烟梗为原料,通过制备烟梗黄原酸酯对废烟梗进行化学改性,并用其吸附Cu^2＋。考察了搅拌速度,吸附剂用量,pH,温度,粒度,Cu^2＋初始浓度和吸附时间对吸附量的影响,发现各种参数对Cu^2＋的吸附都有影响。对于50mg／L的Cu^2＋,吸附平衡时间为10min,吸附量为19．30mg／g,Cu^2＋去除率可达96％。室温下吸附Cu^2＋时,可以用拟二级动力学模型描述。结果表明,化学改性的废烟梗去除Cu^2＋具有良好的应用前景。     

改性稻草秸秆对重金属Pb~(2+)吸附作用研究

以农业废弃物稻草秸秆为原料,经过高锰酸钾和乙二胺改性后,制成对金属离子具有吸附作用的新型吸附材料,研究其对废水中Pb2+吸附效果,对吸附过程pH值和吸附剂投加量的影响以及吸附动力学特征和等温吸附特征进行研究,并将改性稻草秸秆用于鲕状赤铁矿选矿废水混凝后Pb2+深度处理。实验结果表明:改性稻草秸秆对Pb2+具有明显的吸附作用;pH在3~8之间,Pb2+吸附率均可达到80%以上;在室温下,pH为5~5.5,固液比为2 g/L时,吸附时间90 min时,吸附率可达98.7%;吸附过程符合二级动力学吸附过程,饱和吸附容量达到156.9 mg/g;不同浓度下吸附量与平衡浓度之间遵从Freundlich经验公式;混凝后鲕状赤铁矿选矿废水中Pb2+经过改性稻草秸秆深度吸附处理后,可以达到国家排放标准。     

Removal of heavy metal ions from aqueous solution using red loess as an adsorbent

The adsorption behaviors of heavy metals onto novel low-cost adsorbent, red loess, were investigated. Red loess was characterized by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectra. The results indicated that red loess mainly consisted of silicate, ferric and aluminum oxides. Solution pH, adsorbent dosage, initial metal concentration, contact time and temperature significantly influenced the efficiency of heavy metals removal. The adsorption reached equilibrium at 4 hr, and the experimental equilibrium data were fitted to Langmuir monolayer adsorption model. The adsorption of Cu(II) and Zn(II) onto red loess was endothermic, while the adsorption of Pb(II) was exothermic. The maximum adsorption capacities of red loess for Pb(II), Cu(II) and Zn(II) were estimated to be 113.6, 34.2 and 17.5 mg/g, respectively at 25°C and pH 6. The maximum removal efficiencies were 100% for Pb(II) at pH 7, 100% for Cu(II) at pH 8, and 80% for Zn(II) at pH 8. The used adsorbents were readily regenerated using dilute HC1 solution, indicating that red loess has a high reusability. All the above results demonstrated that red loess could be used as a possible alternative low-cost adsorbent for the removal of heavy metals from aqueous solution.